Well here's one use for these rear outlets.....a charge port for my spare battery. It's a marine deep-discharge battery, that could also fit in the Focus. It's a sealed battery, so no fumes or spillage. With jumper cables I can start the Focus, or use it when camping for light, fans, etc. It will also power my laptop computer for a long time....24 hours or more. And numerous other uses.... There's a volt-meter plugged in, so I can check the state of charge. Handy device to have around.... I can bring it into the house for a source of power during an outage. Wouldn't be without one.